All posts by Bryan Swopes

About Bryan Swopes

Bryan R. Swopes grew up in Southern California in the 1950s–60s, near the center of America's aerospace industry. He has had a life-long interest in aviation and space flight. Bryan is a retired commercial helicopter pilot and flight instructor.

21 September 1942

Boeing XB-29 takes off from Boeing Field, Seattle, Washington. (Boeing)
A Boeing XB-29 takes off from Boeing Field, Seattle, Washington. (Boeing)
Edmund T. ("Eddie") Allen
Edmund T. (“Eddie”) Allen

21 September 1942: At Boeing Field, Seattle, Washington, the Boeing Model 345, the first of three XB-29 prototypes, Air Corps serial number 41-002, took off on its first flight.

Edmund T. “Eddie” Allen, Director of Aerodynamics and Flight Research, was in command, with Al Reed, Chief of Flight Test and Chief Test Pilot, as co-pilot. They climbed to 6,000 feet (1,829 meters) and began testing the XB-29’s stability and control, control power and response, and stall characteristics.

The flight was uneventful. Landing after 1 hour, 15 minutes, Allen is supposed to have said, “She flew!”

The XB-29 was 98 feet, 2 inches (29.921 meters) long with a wing span of 141 feet, 3 inches (43.053 meters), and 27 feet, 9 inches (8.458 meters) high to the top of its vertical fin. The prototype bomber had a gross weight of 105,000 pounds (47,627 kilograms).

Boeing XB-29-BO, 41-002, the first XB-29 built. (U.S. Air Force)
Boeing XB-29-BO, 41-002, the first of three prototypes. (U.S. Air Force)

The prototype bomber was powered by four air-cooled, supercharged and fuel-injected 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division Duplex-Cyclone 670C18H1 (R-3350-13) twin-row 18-cylinder radial engines with a compression ratio of 6.85:1. The R-3350-13 was rated at 2,000 horsepower at 2,400 r.p.m., and 2,200 horsepower at 2,800 r.p.m. for takeoff, burning 100-octane gasoline. These engines drove 17-foot-diameter (5.182 meters) three-bladed Hamilton Standard constant-speed propellers through a gear reduction of 0.35:1. The R-3350-13 was 76.26 inches (1.937 meters) long, 55.78 inches (1.417 meters) in diameter, and weighed 2,668 pounds (1,210 kilograms). Wright built 50 of these engines.

Boeing XB-29 Superfortress 41-18335. This is the third prototype. (Boeing)

The XB-29 had a maximum speed of 368 miles per hour (592 kilometers per hour) and cruised at 255 miles per hour (410 kilometers per hour). Its service ceiling was 32,100 feet (9,784 meters).

The airplane was designed to carry 20,000 pounds (9,072 kilograms) of bombs. Though the prototypes were unarmed, the production B-29s were defended by 10 Browning AN-M2 .50-caliber machine guns in four remotely-operated power turrets, with 2 more .50-caliber machine guns and a single AN-M2 20mm autocannon in the tail.

Boeing B-29A-30-BN Superfortress 42-94106, circa 1945. (U.S. Air Force)
Boeing B-29A-30-BN Superfortress 42-94106, circa 1945. (U.S. Air Force)

The B-29 Superfortress was the most technologically advanced—and complex—aircraft of the War. It required the manufacturing capabilities of the entire nation to produce. Over 1,400,000 engineering man-hours had been required to design the prototypes. It was manufactured by Boeing at Seattle and Renton, Washington, and at Wichita, Kansas; by the Glenn L. Martin Company at Omaha, Nebraska; and by Bell Aircraft Corporation, Marietta, Georgia. There were three XB-29 prototypes, 14 YB-29 pre-production test aircraft, 2,513 B-29, 1,119 B-29A, and 311 B-29B Superfortress aircraft. The bomber served during World War II and the Korean War and continued in active U.S. service until 1960.

The first prototype, 41-002, was scrapped in 1948.

© 2017, Bryan R. Swopes

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21 September 1937

Jackie Cochran sits in the cockpit of the Seversky SEV-S1, NR18Y. Note how the landing gear retracts straight to the rear in this early version. It would be modified to retract inward to the airplane’s centerline, and more effectively streamlined in the future.

21 September 1937: Jackie Cochran flew a Seversky Aircraft Corporation SEV-S1, civil registration NR18Y, over a 3 kilometer course at Detroit Wayne County Airport, Romulus, Michigan, averaging 470.40 kilometers per hour (292.29 miles per hour). This was a new Fédération Aéronautique Internationale (FAI) speed record.¹

The Seversky SEV-S1 Executive was an improved version of the P-35 fighter, which was the first U.S. Army Air Corps single engine airplane to feature all-metal construction, an enclosed cockpit and retractable landing gear. It was designed by Major Alexander P. de Seversky. The airplane had been built as the SEV-2XP, a two-place monoplane with fixed landing gear, powered by an air-cooled, supercharged 1,666.860-cubic-inch-displacement (27.315 liter) Wright Aeronautical Division GR1670 two-row, 14-cylinder radial engine. The GR1670A1 had a compression ratio of 6.75:1 and was rated at 775 horsepower at 2,400 r.p.m., and 830 horsepower at 2,400 r.p.m. for takeoff. The GR1670B2C had a compression ratio of 7.0:1 and was rated at 750 horsepower at 2,500 r.p.m., and 850 horsepower at 2,600 r.p.m., for takeoff. These were developmental engines. Both variants had a propeller gear reduction ratio of 16:11. The SEV-2XP was to be a second entry, along with the SEV-1XP, to enter a fly-off at Wright Field. When it was damaged, though, it was rebuilt as a single place airplane with retractable landing gear and a 1,000-horsepower Wright Cyclone GR-1820G4 nine-cylinder engine, and designated SEV-1XP.

 The Seversky's passenger compartment was accessed through a hatch on the right side of the fuselage. (San Diego Air and Space Museum Archives) Jackie Cochran in the cockpit of the Seversky SEV-2S Executive, NR18Y. Note the passenger windows below and behind the cockpit. (San Diego Air and Space Museum Archives)
The Seversky’s passenger compartment was accessed through a hatch on the right side of the fuselage. (San Diego Air and Space Museum Archives)

After the Air Corps demonstrations, which resulted in an order for 100 P-35s, NX18Y was again repowered, this time with an air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney Twin Wasp S1B3-G (R-1830-11) two-row 14-cylinder radial engine with a compression ratio of 6.7:1. The R-1830-11 was rated at 850 horsepower at 2,450 r.p.m. at 5,000 feet (1,524 meters), and 1,000 horsepower at 2,600 r.p.m. for take off, burning 87-octane gasoline. The engine turned a three-bladed Hamilton-Standard controllable-pitch propeller through a 3:2 gear reduction. The R-1830-11 was 4 feet, 8.66 inches (1.439 meters) long with a diameter of 4 feet, 0.00 inches (1.219 meters), and weighed 1,320 pounds (599 kilograms).

With the R-1830, NR18Y was again redesignated SEV-S1. It was flown by Seversky’s chief test pilot, Frank Sinclair, at the 1937 National Air Races and the Bendix Trophy Race.

Major Alexander P. de Seversky and Jackie Cochran with a Seversky monoplane, circa 1937.
Major Alexander P. de Seversky and Jackie Cochran with a Seversky monoplane, circa 1937.

¹ FAI Record File Number 12026

© 2017, Bryan R. Swopes

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20 September 1958

Avro Vulcan VX770.
The first of two prototypes, Avro Type 698 VX770. (BAE Systems)

20 September 1958: The first prototype Avro Vulcan strategic bomber, VX770, piloted by Rolls-Royce test pilot Keith R. Sturt, was on a test flight from the Rolls-Royce Flight Test Establishment, RAF Hucknall, when it diverted to make a scheduled fly-past for an air show being held at RAF Syerstone in Nottinghamshire. Also aboard were Co-Pilot Ronald W. Ward of Fairey Aviation; Rolls-Royce Flight Engineer William E. Howkins; and Navigator, Flight Lieutenant Raymond M. (“Polly”) Parrott, Royal Air Force.

VX770 approched RAF Syerstone at 12:57 p.m. (GMT) and flew east along Runway 07-25 at about 250 feet (76 meters). As the Vulcan passed the control tower at an estimated speed of 350 knots, it began a right turn.

Seen from below, VX770 shows the full delta wing of the prototype. Production aircraft used a modified wing with curved leading edges in order to delay compressibility effects at high speeds. (Unattributed)
Seen from below, VX770 shows the full delta wing of the prototypes. Production aircraft used a modified wing with curved leading edges in order to delay compressibility effects at high speeds. (Unattributed)

Witnesses saw a “kink” form in the leading edge of the Vulcan’s right wing, which then began to disintegrate from the leading edge aft. Wing surface panels could be seen being stripped off before the wing spar failed completely. Clouds of fuel from ruptured tanks trailed as the bomber rolled to the left. The top of the vertical fin came off, the nose pitched upward toward vertical, then straight down, and with both wings on fire, the airplane crashed near the east end of the runway.

All four crew members were killed as were three RAF fire/rescue personnel on the ground. Several others were injured.

The right wing of Avro Vulcan VX770 disintegrates.
The right wing of Avro Vulcan VX770 disintegrates. (© Mary Evans/The National Archives, London, England)
Clouds of vaporized fuel trail the doomed bomber.
Clouds of vaporized fuel trail the doomed bomber. (Unattributed)
Vulcan VX770 crashed at the east end of Runway 07-25.
Vulcan VX770 crashed at the east end of Runway 07-25. Debris spread over 1,400 feet (427 meters). (MEV-10473694 © Mary Evans/The National Archives, London, England)

A short video clip of the fly-by and crash can be seen on You Tube:

The cause of the Vulcan’s wing failure was not determined. Metal fatigue was suspected. The airplane had been used in flight testing for six years and it is possible that it’s design limits may have been exceeded. There was also speculation that vibrations from the new Rolls-Royce Conway “bypass turbojet” engine, which is now called a turbofan, may have weakened the wing.

According to the investigative report, Keith Sturt (b. 20 April 1929) was considered to be an “above average” and “capable and careful” pilot. He had accumulated 1,644 hours of flight over six years. He had flown VX770 for 91 hours, 40 minutes. Sturt was a former Flight Lieutenant in the Royal Air Force, having been inducted into the service in 1945.

VX770 was the first of two Type 698 prototypes built by A.V. Roe & Co., Ltd., at Woodford, Cheshire. It made its first flight 30 August 1951 with Chief Test Pilot R.J. “Roly” Falk. Originally equipped with Rolls-Royce Avon R.A.3 turbojet engines, these were soon replaced with more powerful Armstrong Siddely Sapphire A.S.Sa.6 engines. During modification in 1953, fuel cells were added to the wings. As production airplanes were built with Bristol Olympus Mk.102 engines, VX770 was modified accordingly. During its final flight, Rolls-Royce Conway RCo.10 turbofan engines were installed.

© 2015, Bryan R. Swopes

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20 September 1943

Geoffrey de Havilland, Jr., exits the cockpit of one of the company's jet aircraft. (Photograph Courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Geoffrey de Havilland, Jr., exits the cockpit of one of the company’s jet aircraft. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

20 September 1943: Geoffrey Raoul de Havilland, Jr., chief test pilot of the de Havilland Aircraft Co., Ltd., made the first flight in the prototype DH.100, LZ548/G, at Hatfield, Hertfordshire. (The “/G” in the identification indicated that the aircraft was to be guarded at all times.) Assigned the code name Spider Crab,  the production DH.100 would be better known as the de Havilland Vampire.

The flight lasted approximately 30 minutes and the airplane exceeded 400 miles per hour (644 kilometers per hour). De Havilland reported that the prototype was trimmed with the left wing down, had overly sensitive ailerons and demonstrated instability in yaw with rudder applications.

This oscillation in the yaw axis—called “snaking”—was determined to be a result of the overly effective vertical fins. After wind tunnel and flight testing, it was decided to reduce the fins’ area, resulting in the flat top configuration seen in bottom photograph.

Right front view of the first prototype de Havilland DH.100, LZ548/G.
Right front view of the first prototype de Havilland DH.100, LZ548/G, prior to its first flight. The letter “P” in a circle next to the RAF insignia identifies the airplane as a prototype. The “/G” in the identification number indicates that a guard is required at all times. (De Havilland Aircraft Co., Ltd.)

The DH.100 was a single-seat, single-engine fighter powered by a turbojet engine. The twin tail boom configuration of the airplane was intended to allow a short exhaust tract for the engine, reducing power loss in the early jet engines available at the time.

Right side view of the de Havilland DH.100 Spider Crab LZ548/G.
Right side view of the de Havilland DH.100 Spider Crab LZ548/G.

LZ548/G was originally powered by a Halford H.1 turbojet which produced 2,300 pounds of thrust (10.231 kilonewtons) at 9,300 r.p.m. This engine was produced by de Havilland and named Goblin.

av_gb_4603_jet-history_goblin_p080_w     The Goblin is a linear descendant of the early Whittle units. It comprises a single-sided centrifugal compressor delivering air to sixteen combustion chambers grouped symmetrically around the axis of the unit and leading to the nozzle of the single-stage axial turbine which drives the compressor. Compressor impeller and turbine rotor are coupled by a tubular shaft to form a single rotating assembly which is mounted on only two ball bearings. The maximum diameters of the engine, around the compressor casing, is 50in., [1.27 meters] and with a jet pipe of minimum length fitted the overall length is about 8ft. [2.438 meters] Equipped with a jet pipe and all the necessary engine auxiliaries the dry weight of the complete unit is 1,500 lb. [680 kilograms] Fuel consumption is at the rate of 1.23 lb. / hr. per lb. thrust.

FLIGHT and AIRCRAFT ENGINEER, No. 1923. Vol. XLVIII. Thursday, 1 November 1945 at Page 472, Column 2

The Vampire entered service with the Royal Air Force in 1945 and remained a front-line fighter until 1953. 3,268 DH.100s were built.

Right rear quarter view of the prototype de Havilland DH.100, LZ548/G.
Right rear quarter view of the prototype de Havilland DH.100, LZ548/G. In this photograph, the airplane’s vertical fins have been squared off. This would be a feature of the production Vampire F.1.

The first of the three prototype Vampires, LZ548, crashed after takeoff from Hatfield, 23 July 1945, due to a fuel pump failure. Geoffrey Pike, the pilot, was not injured.

© 2016, Bryan R. Swopes

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20 September 1904

Wilbur Wright, 1867–1912. (Library of Congress)

20 September 1904: In an effort to improve their airplane, the Wright Brothers moved their test flights from the windy Kill Devil Hills of North Carolina to Huffman Prairie, near Dayton, Ohio. Without the winds, however, they needed to achieve greater speed for the airplane to take off, so they devised a catapult which used a 1,200 pound (544 kilogram) weight dropped from a 20 foot (6.1 meter) wooden derrick to pull the Wright Flyer II down a wooden track.

The Wright Flyer II was very similar to the original Flyer. Some parts of the airframe were strengthened, which slightly increased the new airplane’s weight.

Wilbur Wright was at the controls of the Flyer II on 20 September 1904, when it made the first-ever complete circular turn by an airplane. This was witnessed by Ames I. Root, who wrote about it in his magazine, Gleanings in Bee Culture:

“When it turned that circle, and came near the starting-point, I was right in front of it, and I said then and I believe still, it was. . . the grandest sight of my life. Imagine a locomotive that has left its track, and is climbing right toward you – a locomotive without any wheels. . . but with white wings instead. . . Well, now, imagine that locomotive with wings that spread 20 feet each way, coming right toward you with the tremendous flap of its propellers, and you have something like what I saw.”

The 30th flight of Flyer II at Huffman Prairie, August 1904. (Wright State University)

The Wright Brothers flew the Flyer II 105 times that summer. Next would come the Flyer III.

Wilbur Wright and the Flyer II on Flight 85 at Huffman Prairie. (Wright State University)

© 2015, Bryan R. Swopes

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